In orthopedics there is value in determining the relative motion of two or more rigid bodies such as bone segments and bone implants. X-ray imaging is generally used to determine relative position and orientation of bone structures and implants. Radiostereometric analysis or roentgen stereophotogrammetric analysis (RSA) is a method of obtaining two simultaneous x-ray exposures of the same implant/bone structure to determine the relative positions between multiple bone segments, between bone and implant, or between multiple implants.
The use of RSA requires the implantation of radiopaque markers into the bone. Markers are currently implanted during surgery; however, this process can be time consuming. In addition, the surgical implantation of markers generally does not necessarily provide the desired accuracy. Accurate positioning of these markers improves the motion analysis results.
Accordingly, there is a need for a method which overcomes one or more of the disadvantages associated with radiopaque markers in bone for imaging purposes.